io.atomix.coordination

Interface MessageConsumer<T>

public interface MessageConsumer<T>

Message bus topic consumer.

Message consumers listen for messages from MessageProducers for a topic(). Multiple consumers may listen to the same topic from the same or different nodes within the cluster. Producers route messages to consumers in round-robin order, so if multiple consumers are registered for the same topic, messages will be evenly split among them.

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Method Summary

Modifier and Type	Method and Description
CompletableFuture<Void>	close() Closes the consumer.
MessageConsumer<T>	onMessage(Function<T,?> consumer) Sets a message consumer callback.
String	topic() Returns the topic for which the consumer consumes messages.

Method Detail

topic

String topic()

Returns the topic for which the consumer consumes messages.

Returns:

The topic for which the consumer consumes messages.

onMessage

MessageConsumer<T> onMessage(Function<T,?> consumer)

Sets a message consumer callback.

The provided Function will be called when a message is received from a MessageProducer. Function return values are sent back to the producer as response values. The function can return a synchronous value or a CompletableFuture. Consumer return values are handled transparently. If a consumer returns a future, the message bus will wait for the future to be completed before sending a response.

Parameters:

consumer - The callback to call when a message is received by the consumer.

Returns:

The message consumer.

Throws:

NullPointerException - if consumer is null

close

CompletableFuture<Void> close()

Closes the consumer.

Returns:

A completable future to be completed once the consumer has been closed.